iommu/amd: Add SVA domain support

- Allocate SVA domain and setup mmu notifier. In free path unregister
  mmu notifier and free protection domain.

- Add mmu notifier callback function. It will retrieve SVA protection
  domain and invalidates IO/TLB.

Signed-off-by: Vasant Hegde <[email protected]>

Author: hegdevasant

drivers/iommu/amd/amd_iommu.h

@@ -45,6 +45,11 @@ extern enum io_pgtable_fmt amd_iommu_pgtable;
 extern int amd_iommu_gpt_level;
 
 /* Protection domain ops */
+struct protection_domain *protection_domain_alloc(unsigned int type);
+void protection_domain_free(struct protection_domain *domain);
+struct iommu_domain *amd_iommu_domain_alloc_sva(struct device *dev,
+						struct mm_struct *mm);
+void amd_iommu_domain_free(struct iommu_domain *dom);
 int iommu_sva_set_dev_pasid(struct iommu_domain *domain,
 			    struct device *dev, ioasid_t pasid);
 void amd_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid);

drivers/iommu/amd/amd_iommu_types.h

@@ -588,6 +588,7 @@ struct protection_domain {
 	unsigned dev_cnt;	/* devices assigned to this domain */
 	unsigned dev_iommu[MAX_IOMMUS]; /* per-IOMMU reference count */
 
+	struct mmu_notifier mn;	/* mmu notifier for the SVA domain */
 	struct list_head pasid_list; /* List of pdom_pasid_data */
 };
 

drivers/iommu/amd/iommu.c

@@ -2280,7 +2280,7 @@ static void cleanup_domain(struct protection_domain *domain)
 	WARN_ON(domain->dev_cnt != 0);
 }
 
-static void protection_domain_free(struct protection_domain *domain)
+void protection_domain_free(struct protection_domain *domain)
 {
 	if (!domain)
 		return;
@@ -2323,7 +2323,7 @@ static int protection_domain_init_v2(struct protection_domain *pdom)
 	return 0;
 }
 
-static struct protection_domain *protection_domain_alloc(unsigned int type)
+struct protection_domain *protection_domain_alloc(unsigned int type)
 {
 	struct io_pgtable_ops *pgtbl_ops;
 	struct protection_domain *domain;
@@ -2346,6 +2346,7 @@ static struct protection_domain *protection_domain_alloc(unsigned int type)
 	switch (type) {
 	/* No need to allocate io pgtable ops in passthrough mode */
 	case IOMMU_DOMAIN_IDENTITY:
+	case IOMMU_DOMAIN_SVA:
 		return domain;
 	case IOMMU_DOMAIN_DMA:
 		pgtable = amd_iommu_pgtable;
@@ -2465,7 +2466,7 @@ amd_iommu_domain_alloc_user(struct device *dev, u32 flags,
 	return do_iommu_domain_alloc(type, dev, flags);
 }
 
-static void amd_iommu_domain_free(struct iommu_domain *dom)
+void amd_iommu_domain_free(struct iommu_domain *dom)
 {
 	struct protection_domain *domain;
 	unsigned long flags;
@@ -2833,6 +2834,7 @@ static int amd_iommu_dev_enable_feature(struct device *dev,
 
 	switch (feat) {
 	case IOMMU_DEV_FEAT_IOPF:
+	case IOMMU_DEV_FEAT_SVA:
 		break;
 	default:
 		ret = -EINVAL;
@@ -2848,6 +2850,7 @@ static int amd_iommu_dev_disable_feature(struct device *dev,
 
 	switch (feat) {
 	case IOMMU_DEV_FEAT_IOPF:
+	case IOMMU_DEV_FEAT_SVA:
 		break;
 	default:
 		ret = -EINVAL;
@@ -2860,6 +2863,7 @@ const struct iommu_ops amd_iommu_ops = {
 	.capable = amd_iommu_capable,
 	.domain_alloc = amd_iommu_domain_alloc,
 	.domain_alloc_user = amd_iommu_domain_alloc_user,
+	.domain_alloc_sva = amd_iommu_domain_alloc_sva,
 	.probe_device = amd_iommu_probe_device,
 	.release_device = amd_iommu_release_device,
 	.probe_finalize = amd_iommu_probe_finalize,

drivers/iommu/amd/pasid.c

@@ -120,6 +120,53 @@ static void remove_pdom_dev_pasid(struct protection_domain *pdom,
 	}
 }
 
+static void sva_arch_invalidate_secondary_tlbs(struct mmu_notifier *mn,
+				    struct mm_struct *mm,
+				    unsigned long start, unsigned long end)
+{
+	struct pdom_pasid_data *pasid_data;
+	struct protection_domain *sva_pdom;
+	struct iommu_dev_data *dev_data;
+	unsigned long flags;
+
+	sva_pdom = container_of(mn, struct protection_domain, mn);
+
+	spin_lock_irqsave(&sva_pdom->lock, flags);
+
+	list_for_each_entry(pasid_data, &sva_pdom->pasid_list, pdom_link) {
+		dev_data = pasid_data->dev_data;
+
+		amd_iommu_dev_flush_pasid_pages(dev_data, pasid_data->pasid,
+						start, end - start);
+	}
+
+	spin_unlock_irqrestore(&sva_pdom->lock, flags);
+}
+
+static void sva_mn_release(struct mmu_notifier *mn, struct mm_struct *mm)
+{
+	struct pdom_pasid_data *pasid_data, *next;
+	struct protection_domain *sva_pdom;
+	unsigned long flags;
+
+	sva_pdom = container_of(mn, struct protection_domain, mn);
+
+	spin_lock_irqsave(&sva_pdom->lock, flags);
+
+	/* Assume pasid_list contains same PASID with different devices */
+	list_for_each_entry_safe(pasid_data, next,
+				 &sva_pdom->pasid_list, pdom_link) {
+		remove_dev_pasid(pasid_data);
+	}
+
+	spin_unlock_irqrestore(&sva_pdom->lock, flags);
+}
+
+static const struct mmu_notifier_ops sva_mn = {
+	.arch_invalidate_secondary_tlbs = sva_arch_invalidate_secondary_tlbs,
+	.release = sva_mn_release,
+};
+
 int iommu_sva_set_dev_pasid(struct iommu_domain *domain,
 			    struct device *dev, ioasid_t pasid)
 {
@@ -191,3 +238,40 @@ void amd_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
 
 	spin_unlock_irqrestore(&sva_pdom->lock, flags);
 }
+
+static void iommu_sva_domain_free(struct iommu_domain *domain)
+{
+	struct protection_domain *sva_pdom = to_pdomain(domain);
+
+	if (sva_pdom->mn.ops)
+		mmu_notifier_unregister(&sva_pdom->mn, domain->mm);
+
+	amd_iommu_domain_free(domain);
+}
+
+static const struct iommu_domain_ops amd_sva_domain_ops = {
+	.set_dev_pasid = iommu_sva_set_dev_pasid,
+	.free	       = iommu_sva_domain_free
+};
+
+struct iommu_domain *amd_iommu_domain_alloc_sva(struct device *dev,
+						struct mm_struct *mm)
+{
+	struct protection_domain *pdom;
+	int ret;
+
+	pdom = protection_domain_alloc(IOMMU_DOMAIN_SVA);
+	if (!pdom)
+		return ERR_PTR(-ENOMEM);
+
+	pdom->domain.ops = &amd_sva_domain_ops;
+	pdom->mn.ops = &sva_mn;
+
+	ret = mmu_notifier_register(&pdom->mn, mm);
+	if (ret) {
+		protection_domain_free(pdom);
+		return ERR_PTR(ret);
+	}
+
+	return &pdom->domain;
+}